While most iPhone rumors should be taken with a pinch of salt, sometimes they’re backed by hard, irrefutable evidence. This report seems to be one of those.

A photo of the battery, which appeared on 9to5Mac, shows a 1440 mAh model that’s only marginally better than the 1420 mAh unit that powers the iPhone 4S. If the new battery had been used in the 4S, the difference in battery life would be negligible. How it’s going to perform in a more powerful iPhone 5 has me wondering.

Bear in mind that other rumored features — which I think are real one — will require significant more power. Among them: a bigger screen, LTE, Apple turn-by-turn mapping and dual-core processing.

Should We Be Worried?

Apple likely tested the new phone carefully and is aiming for something that can maintain power through a full day of regular use. You have to figure it also wants to see battery life that is the same, or better, than the iPhone 4S’s.

But how can they do that with a battery that’s only slightly larger, when the device consumes more power? The answer is simple: better power management. There’s been a good deal of research into lately and, in every published study that I’ve seen, Apple has probably secretly funded several of them.